The invention relates to a method of producing a rotor for rotary slide-vane vacuum pumps. The invention further relates to a rotor produced by said method.
Production of the rotor poses a special problem in the manufacture of rotary slide-vane vacuum pumps. For example, the overall dimensions of the rotor should have tight tolerances, for reasons of quiet operation and minimum wear of the pump. This condition can be substantially satisfied through one-piece construction of the rotor, for example. The rotor can then be machined completely without the workholding fixture being changed, with the result that the outside measurements of the rotor have very small tolerances relative to one another. However, with a one-piece rotor the production of the slots for the slide vane or vanes is possible only by immersed machining, which makes it complicated and expensive, especially when the slots extend through the entire rotor and therefore must be machined very accurately for reasons of tightness.
From U.S. Pat. No. 2,782,725 it is known to produce the rotor of a rotary slide-vane machine in two sections. To permit the two rotor sections to be joined properly centered after their production, their front edges are provided with mating projections and recesses. A drawback of this arrangement is that the rotor section, and particularly the projections and recesses, must be produced to extremely close tolerances. The accuracy requirements become all the more stringent as the required rotative speed of the pump increases.